Rettungsoperationen und deren Differenzialindikation am distalen Radioulnargelenk

The most common cause of an arthritically damaged distal radioulnar joint is a malunion of a distal radius fracture. Therapeutically, ulnar head resection, hemiresection-interposition-technique, Kapandji-Sauvé procedure and implantation of an ulnar head prosthesis have been described. None of these procedures is able to restore the complete function of the joint. Therefore, anatomical reconstruction of the joint in acute or secondary correction osteotomy for malunited fractures of the distal radius should be performed to avoid the development of the arthrosis. Numerous clinical studies have demonstrated a similar reduction of the clinical symptoms for all procedures. Therefore, classification of the different procedures has to consider the number of complications. Biomechanically, partial resection of the distal ulna will destabilize the distal radioulnar context and clinically may lead to painful radioulnar and/or dorsopalmar instability of the distal ulnar stump. Biomechanically and clinically, this complication, next to secondary extensor tendon ruptures, has to be expected far more often following complete resection of the ulnar head than in the alternative procedures. We do not see any remaining indication for complete resection of the ulnar head. Clinical results and the occurrence of painful instability of the distal ulnar stump have been reported almost identically for the hemiresection-interposition technique and the Kapandji Sauvé procedure. Therefore, both procedures appear to be equally suitable for the treatment of painful arthrosis of the distal radioulnar joint. In patients with a preexisting instability of the distal radioulnar joint, or a major deformity of the radius or the ulna, we prefer to perform the hemiresection-interposition-technique. In these conditions we consider the remaining contact of the triangular fibrocartilage complex with the distal end of the ulna a biomechanical advantage to reduce the risk of secondary instability. Biomechanically as well as clinically, replacement of the ulnar head using a prosthesis has been shown to either avoid or solve the problem of instability. We therefore consider ulnar head replacement the treatment of choice in secondary painful instability following resection procedures at the distal end of the ulna. Primary ulnar head replacement should be considered in special indications until long-term follow-up results are available.